The present invention relates to walking canes.
The present invention more particularly relates to walking canes adapted for use on icy and slippery surfaces, as well as on non-slippery surfaces.
One problem with conventional walking canes is that when a person extends the cane forwardly, in order to take a step, the cane is then slightly oblique to the walking surface. If the sidewalk, pavement, or other walking surface, is icy, the lower end of the cane may tend to slide forwardly along the walking surface, thereby causing the person to lose his or her balance.
Another problem concerns operation of the cane on soft terrain, such as loose gravel, sand, or soft earth. An ordinary cane has a rubber cup on its lower end, adapted to resiliently deform and grip the walking surface. When the walking surface is soft, or loose, the lower end of the cane tends to sink into the soft surface, so that the person has a tendency to topple sidewise when he, or she, puts any weight on the cane. The rubber cup on the lower end of the cane will not support the cane on soft terrain.
Various cane, or crutch, constructions have been devised to overcome the above-noted problems. U.S. Pat. No. 3,177,884, granted to W. C. Thro, on Apr. 13, 1965, discloses a crutch, having a rubber cup, that has an internally threaded insert in its lower wall. A removable spike structure can be threaded into the threaded insert, so that the tip of the spike extends axially downwardly, from the shaft portion of the crutch, or cane.
The cane construction of U.S. Pat. No. 3,177,884 would presumably have some utility on icy surfaces, in that the spike could possibly be made to penetrate and embed itself in the ice layer, thereby tending to prevent the cane tip area from sliding along the ice surface. However, it is doubtful that the cane would be usable on soft terrain, since the rubber cup would tend to sink into such terrain. The rubber cup has only a relatively small end area in contact with the terrain surface, so that the rubber cup will not prevent the cane from sinking into soft terrain.
U.S. Pat. No. 4,098,283, issued to R. Tritle, on Jul. 4, 1978, shows a rubber cup, attachable to the lower end of a crutch or cane. A circular disk is secured to the lower face of the cup. As shown in FIG. 3, of the patent, the lower face of the disk has a slight convex curvature. At its peripheral edge, the circular disk has an annular ridge. The patentee indicates that the annular ridge will cut in-to and grab a sand surface. Apparently a cane equipped with the cup-disk assembly can be used on sand, ice, or snow.
One potential problem with the circular disk construction of U.S. Pat. No. 4,098,283 is that when the person extends the cane forwardly to begin a step, the circular disk will initially engage the walking surface at a particular point on the annular ridge. If the walking surface is hard, the disk may tend to roll laterally, with the annular ridge acting as a small wheel. Such a rolling motion could cause the cane to slip out from underneath the person's hand.
U.S. Pat. No. 5,103,850, issued to R. C. Davis, on Apr. 14, 1992, shows a crutch construction, having a flared base at its lower end. The bottom surface of the base has a convex arcuate shape, so that the base can have a rocking motion on the walking surface. The flared base is provided with a resilient elastomeric boot that fits onto its arcuate bottom surface. The arcuate surface of the boot is resilient, so as to have a gripping action on the subjacent walking surface.
A deficiency of the cane, or crutch, of U.S. Pat. No. 5,103,850 is that it has minimal utility on icy surfaces. The curved elastomeric surface of the boot could not be expected to grip an icy surface. More likely, the curved rubber surface would tend to slide on icy surfaces.